ABSTRACT This proposal is to add a version of the second wave of the Aging, Demographic and Memory Study (ADAMS), now called the Harmonized Cognition Assessment Protocol (HCAP), pioneered by the Health and Retirement Study (HRS) in the United States, to wave 4, in 2018, of the China Health and Retirement Longitudinal Study (CHARLS). The importance of research on Alzheimer?s Disease and related disorders (ADRD), among the elderly is recognized in the United States where the HRS has pioneered the ADAMS study, which allowed pioneering estimates of prevalence of dementia and cognitive impairment without dementia among the US elderly population. A burning question is how these US results compare to results from other countries, using a harmonized method to elicit prevalence rates. There have been a large number of studies measuring dementia and exploring some correlates of dementia in China. However, none of these is from a publicly available, nationally representative survey and these earlier studies did not have available the richness of data to complement the cognition data that CHARLS has. We will focus the CHARLS HCAP on respondents aged 65 and older, as does the HRS in its HCAP. The overarching goal is to add a battery of questions to CHARLS that can be used to evaluate Alzheimer?s Disease and related disorders and progression to ADRD among the Chinese elderly. We expect 7,658 wave 4 respondents who are age 65 and older. We will interview all of them for the CHARLS HCAP. The plan is to make this part of CHARLS in every other wave (a six year frequency in the future) starting in 2018. This proposal is to develop, pilot, pretest, validate and field the first CHARLS HCAP. As we did with the CHARLS data to date, we will make these data publicly available, together with complete documentation, within one year after collection. Adding the CHARLS HCAP will allow researchers to follow cognition and other conditions related to ADRD over time. In addition, many cognition and other dementia-related variables on the same individuals in the past are available starting in wave 1. We will also have a formal validation sample of just over 3,000 individuals aged 65 and older to validate the HCAP tests against assessments made by physicians. CHARLS is the first nationally representative and publicly available aging data set on China. It is a bi- annual survey, directly patterned on the HRS and its sister surveys in England, Continental Europe, India, Japan, Indonesia and South Korea. The CHARLS national baseline data, collected in 2011-12, were released publicly in early 2013, 11 months after completing field operations. Wave 2 was fielded in the summer and fall of 2013 and made public in early 2015. A special life history wave was fielded in the summer and fall of 2014 and will be public early 2016. Wave 3 of CHARLS was fielded in the summer and fall of 2015 and wave 4 in 2018.